Deckle Technology

ABSTRACT

The invention provides a deckle system for extrusion dies. In certain embodiments, the invention provides methods of cleaning an extrusion die equipped with a retractable external deckle system. Also provided in some embodiments is a deckle system having a novel deckle adjustment mechanism. In other embodiments, the invention provides an advantageous internal deckle member equipped with a removable, replaceable internally threaded insert.

FIELD OF THE INVENTION

The present invention relates generally to deckle systems for dies.Specifically, this invention relates to internal and external decklesfor extrusion dies.

BACKGROUND OF THE INVENTION

A variety of deckle systems are known for extrusion dies. A decklesystem defines the width of the extrudate, as is well known to peopleskilled in this area of technology. The deckles on an extrusion die maybe internal, external, or both.

One problem with conventional deckle systems is that cleaning mayrequire substantial time and effort. For example, the operator may needto spend long periods of time taking apart the deckle system, andremoving it from the die, before it is possible to clean the transitionzone connecting the preland channel and the final land channel.Depending on the particular die/deckle being used, it may take on theorder of 1-2 hours to perform a single cleaning. Given the importance oflean production in today's manufacturing environment, the need todisassemble a deckle prior to cleaning is a considerable drawback.

With respect to external deckles, U.S. Pat. Nos. 3,797,987 and 5,830,391show external deckles where a sealing bar is pressed against, andthereby blocks, the die orifice. The sealing bar, however, does notextend into the orifice or into the final land channel. Instead, thesealing bar is merely seated against the outside of the orifice. As aconsequence, the results achieved with external deckles of this naturemay be less than ideal.

With respect to internal deckles, the conventional mechanisms that areused to adjust the positioning of internal deckles could be improved inmany cases. For example, it would be desirable to provide deckleadjustment mechanisms that can provide relatively rapid travel of aninternal deckle during adjustment.

Further, it is common to have an internal deckle blade that defines aninternally threaded bore adapted to receive an externally threadedcontrol shaft. While this arrangement has generally been acceptable, theinternal threading of the deckle blade is sometimes damaged. If thedamage is severe enough, then the whole deckle blade may need to bereplaced, even though the rest of the deckle blade may be in goodcondition. Needless to say, this is wasteful and expensive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a deckle system in accordance withcertain embodiments of the present invention.

FIG. 2 is another perspective view of the deckle system of FIG. 1.

FIG. 3 is a partially broken-away elevation view of the distal endregion of the deckle system of FIG. 1.

FIG. 4 is a elevation view of the deckle system of FIG. 1.

FIG. 5 is a perspective view of an external deckle system in accordancewith certain embodiments of the invention.

FIG. 6A is another perspective view of the external deckle system ofFIG. 5.

FIG. 6B is an exploded perspective view of the external deckle system ofFIG. 5.

FIG. 7 is a front perspective view of a deckle system mountedoperatively on a die in accordance with certain embodiments of theinvention.

FIG. 8 is a front perspective view of the deckle and die of FIG. 7, withthe external deckle shown in a retracted cleaning position.

FIG. 9 is a front perspective view of the deckle and die of FIG. 7, withthe external deckle shown in the retracted cleaning position and ascraper positioned in a cleaning access of the deckle.

FIG. 10 is a front perspective view of the deckle and die of FIG. 7,with the external deckle shown in the retracted cleaning position andthe scraper positioned in the die.

FIG. 11 is a cross-sectional view of the die of FIG. 10, showing thescraper positioned in the die.

FIG. 12 is a partially broken-away front perspective view of a decklesystem in accordance with certain embodiments of the invention.

FIG. 13 is a partially broken-away front perspective view of the decklesystem of FIG. 12, shown from another front perspective.

FIG. 14 is a cross-sectional view of a die having a final land channelinto which extends a blade projecting from an external deckle inaccordance with certain embodiments of the invention.

FIG. 15 is a partially broken-away cross-sectional view of an internaldeckle member having an interior bore in which a removable internallythreaded sleeve is mounted in accordance with certain embodiments of theinvention.

FIG. 16A is a partially broken-away perspective view of a leading endregion of an external deckle in accordance with certain embodiments ofthe invention.

FIG. 16B is a perspective detail view of a subassembly that serves as adeckle adjustment mechanism in accordance with certain embodiments ofthe invention.

FIG. 16C is an end view of the external deckle of FIG. 16A.

FIG. 17A is a partially broken-away front perspective view of a decklesystem in accordance with certain embodiments of the invention, with aquill of the system removed for purposes of illustration.

FIG. 17B is a partially broken-away front perspective view of the decklesystem of FIG. 17A, shown from another front perspective and with thequill in place.

FIG. 18A is a partially broken-away front elevation view of anotherdeckle system in accordance with certain embodiments of the invention.

FIG. 18B is a front perspective view of the deckle system of FIG. 18A.

FIG. 18C is another front perspective view of the deckle system of FIG.18A, with the gear box removed for purposes of illustration.

FIG. 19A is a partially broken-away front elevation view of yet anotherdeckle system in accordance with certain embodiments of the invention.

FIG. 19B is a front perspective view of the deckle system of FIG. 19A.

FIG. 19C is another front perspective view of the deckle system of FIG.19A, with an exterior housing removed to show internal workings.

SUMMARY OF THE INVENTION

In certain embodiments, the invention provides an extrusion die equippedwith a deckle system. In the present embodiments, the die preferably hasa manifold, a preland channel, a final land channel, and an orifice,wherein a transition zone extends from a downstream end region of thepreland channel to an upstream end region of the final land channel. Inthe present embodiments, the deckle system includes an external decklecomprising a retractable base mounted so as to be moveable transverselyrelative to the die, such that the base can be moved transversely awayfrom the orifice far enough to expose a cleaning access through which ascraper can be inserted as part of a process for moving the scraper intoand transversely along the die to clean unwanted material from thetransition zone The cleaning access is spaced transversely away from thedie.

Some embodiments of the invention provide a deckle system that includesan external deckle and an end plate. In the present embodiments, the endplate is configured to be mounted on an end of a die. Preferably, theexternal deckle comprises a retractable base that is moveabletransversely relative to the end plate, such that the retractable basecan be moved transversely away from the end plate so as to expose acleaning access into which a scraper can be inserted. Preferably, a slotopening passing transversely through the end plate opens to the cleaningaccess, such that an access path for the scraper extends through thecleaning access and transversely along the slot opening.

Certain embodiments of the invention provide a method of cleaning anextrusion die. In some of the present methods, the die has a manifold, apreland channel, a final land channel, and an orifice, wherein atransition zone extends from a downstream end region of the prelandchannel to an upstream end region of the final land channel. In thepresent method, the die is equipped with a deckle system that includesan external deckle comprising a retractable base mounted so as to bemoveable transversely relative to the die, such that the base can bemoved transversely away from the orifice far enough to expose a cleaningaccess that is spaced transversely away from the die. The methodcomprises inserting a scraper into the cleaning access and moving thescraper transversely along the die to clean unwanted material from thedie's transition zone.

In some embodiments, the invention provides an extrusion die equippedwith an external deckle. Preferably, the die has a manifold, a prelandchannel, a final land channel, and an orifice. In the presentembodiments, the external deckle has a blade that projects from outsideof the orifice, through the orifice, and into the final land channel,e.g., such that the blade does not extend into the preland channel butrather has an upstream edge that terminates in the final land channel.

The invention in certain embodiments provides a deckle system thatincludes an external deckle comprising a transversely moveable base. Inthe present embodiments, a blade projects from the base and isconfigured to extend through an orifice, and into a final land channel,of a die to which the deckle system can be mounted. Preferably, theblade is mounted removably on the retractable base.

In certain embodiments, the invention provides a deckle system having anovel deckle adjustment mechanism. In the present embodiments, thedeckle adjustment mechanism includes an adjustment beam having a seriesof detent recesses spaced along a transverse length of the beam. Here,the deckle adjustment mechanism includes a lever device operably coupledwith an engagement tooth, wherein by engaging the tooth with a desiredone of the detent recesses and pivoting the lever device in a firstdirection the adjustment beam can be moved in a transverse inwarddirection.

The invention in some embodiments provides a method of adjusting deckleposition on a die equipped with a deckle system. In the present method,the deckle system includes a deckle adjustment device comprising anadjustment beam having a series of detent recesses spaced along atransverse length of the beam. Here, the deckle system includes aninternal deckle member operably coupled to the adjustment beam. In thepresent method, the deckle system has a detent mechanism comprising alever device operably coupled with an engagement tooth. The presentmethod comprises engaging the tooth with one of the detent recesses andpivoting the lever device in a first direction so as to bias theadjustment beam and thereby move the beam transversely inwardly, wherebythe internal deckle member is made to move transversely inwardlytogether with the adjustment beam.

In certain embodiments, the invention provides an internal deckle memberfor an extrusion die. In the present embodiments, the deckle membercomprises an elongated deckle body defining a transverse opening thatopens through a side end of the deckle body and extends inwardly intothe deckle body. Here, an internally threaded sleeve is mounted withinthe blind opening and defines an internally threaded passageway forreceipt of a correspondingly externally threaded shaft. The sleeve ismounted removably within the opening such that if internal threads ofthe sleeve are damaged, then the sleeve can be removed and replaced witha replacement internally threaded sleeve.

Some embodiments of the invention provide a deckle system comprising astationary beam and a movable deckle carrier configured to movetransversely along the stationary beam. In the present embodiments, anovel deckle adjustment mechanism is provided on the moveable decklecarrier. Here, the deckle adjustment mechanism includes an adjustmentbeam comprising a rack with a series of teeth spaced along a transverselength of the rack. The present deckle adjustment mechanism alsoincludes a pinion operably coupled with the rack, such that rotating thepinion in a first direction causes the adjustment beam to move in atransverse inward direction, whereas rotating the pinion in a seconddirection causes the adjustment beam to move in a transverse outwarddirection. Preferably, the adjustment beam is operably coupled to aninternal deckle such that the internal deckle is configured to movetransversely conjointly with the adjustment beam. In the presentembodiments, the deckle adjustment mechanism comprises a control unithaving a locked configuration, a first adjustment configuration, and asecond adjustment configuration. When the control unit is in its lockedconfiguration, the internal deckle is locked against movement in eithertransverse direction; when the control unit is in its first adjustmentconfiguration, the internal deckle is locked against outward transversemovement but is free to move transversely inwardly in response torotation of the pinion in the first direction; when the control unit isin its second adjustment configuration, the internal deckle is lockedagainst inward transverse movement but is free to move transverselyoutwardly in response to rotation of the pinion in the second direction.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The following detailed description is to be read with reference to thedrawings, in which like elements in different drawings have likereference numerals. The drawings, which are not necessarily to scale,depict selected embodiments and are not intended to limit the scope ofthe invention. Skilled artisans will recognize that the given exampleshave many useful alternatives, which fall within the scope of theinvention.

The invention provides a number of novel technologies and features forinternal and external deckle assemblies. In a first group ofembodiments, the invention provides an external deckle for use on anextrusion die. The die D can be provided in any of a variety ofconventional forms, as are well known to those skilled in this field.Generally, the die has a manifold MF, a preland channel PL, a final landchannel LC, and an orifice. Preferably, a transition zone TZ connectsthe preland channel PL and the final land channel (e.g., a transitionzone may extend from a downstream end region of the preland channel toan upstream end region of the final land channel). The transition zonemay comprise two confronting radiused (or otherwise tapered) wallsections, optionally extending from confronting upstream preland wallsections (which may define a preland channel that is wider than thefinal land channel) to confronting downstream final land wall sections(which may define a final land channel that is more narrow than thepreland channel). Reference is made to FIG. 11. The external deckle canbe used with a variety of different extrusion dies, so the particularsof the die itself are not limiting to the invention.

In the present embodiments, the external deckle comprises a retractablebase 50 mounted so as to be moveable transversely (e.g., along atransverse axis, as shown by arrows AA in FIG. 1) relative to the die.Preferably, the retractable base 50 can be moved transversely relativeto the die D such that (when the external deckle is in an unlockedconfiguration), without having to disassemble the external deckle (orthe die), the base can be moved (e.g., independently of deckle carrier120) transversely away from the orifice far enough to expose a cleaningaccess 57 through which a scraper SC can be inserted as part of aprocess for moving the scraper into and transversely along the die toclean unwanted material from the transition zone of the die.

Reference is made to FIGS. 7-10. Here, the external deckle has a lockedconfiguration and an unlocked configuration. When the illustratedexternal deckle is in its locked configuration, the retractable base 50is locked to the movable deckle carrier 120. Thus, when the externaldeckle is in its locked configuration, the retractable base 50 isconfigured to move transversely together with (or “conjointly with”) thedeckle carrier 120. In contrast, when the illustrated external deckle isin its unlocked configuration, the retractable base 50 is free to move(e.g., slide) transversely relative to (i.e., independent of) the decklecarrier 120.

In the illustrated design, the retractable base 50 can be selectivelylocked to, or unlocked from, the deckle carrier 120 by virtue of areleasable connection. For example, an exteriorly threaded fastener 800can be mounted on the retractable base 50 so as to be extendable into aninteriorly threaded opening of the deckle carrier 120. By rotating thefastener 800 far enough in a first direction (e.g., counterclockwise),the fastener can be separated from the carrier's interiorly threadedopening, thus unlocking the base 50 from the deckle carrier 120. This isperhaps best appreciated by referring to FIGS. 5, 6A, 7, and 17B. InFIGS. 5, 6A, and 6B, the threads on the illustrated fastener 800 are notshown, but they would be provided on the exterior of the fastener. It isto be appreciated that this is merely one exemplary releasableconnection that can be used for providing the external deckle withlocked and unlocked configurations. Various other releasable mechanical,magnetic, etc. connections could be used.

As is perhaps best seen in FIG. 8, the cleaning access 57 preferably isspaced transversely away (i.e., apart) from the die D. That is, thecleaning access 57 preferably is at a location external to the die D.Thus, the illustrated cleaning access 57 is defined by the deckle system10, not by the die D. In some embodiments, the cleaning access 57 islocated transversely away from (e.g., outwardly of) an end plate 80 ofthe deckle system 10. More will be said of this later.

With continued reference to FIG. 8, when the illustrated cleaning access57 is exposed (by moving the base 50 transversely away from theorifice), the cleaning access is bounded by a first end region 51 of thebase. The illustrated base 50 has an elongated configuration withopposed first 51 and second 59 end regions. The first end region 51 isadjacent to the die D, and the second end region 59 is remote from thedie. In the illustrated embodiments, the retractable base 50 iselongated in a direction parallel to a transverse length of the die'sorifice (e.g., parallel to the deckle system's transverse axis AA).

With many conventional deckle systems, before it is possible to cleanthe die (e.g., a transition zone thereof), it is necessary to performsome disassembly of the deckle system, the die, or both. In such cases,it may take 1-2 hours to perform a single cleaning. The need to spendconsiderable time on disassembly prior to cleaning is a significantproblem, particularly given the importance of lean manufacturing.

To address this problem, the present embodiments provide a deckle systemthat allows the die D to be cleaned without first having to disassemblethe deckle system. In the illustrated preferred embodiments, this isaccomplished by providing an external deckle that can be readily moved(e.g., transversely away from the die) so as to expose a cleaning access57. Preferably, when the external deckle is in an unlockedconfiguration, it can be moved transversely outwardly relative to (e.g.,independent of) a movable deckle carrier 120 of the deckle assembly soas to expose the cleaning access 57. As will be appreciated by thoseskilled in the present field, this is a great benefit since iteliminates a complication that has plagued many conventional decklesystems.

Referring to FIGS. 1 and 2, the retractable base is identified byreference numeral 50. The base 50 is mounted on the deckle system 10 soas to be movable (e.g., slidable) transversely relative to the die(and/or relative to an end plate 80 of the deckle system). In theembodiment illustrated, the retractable base 50 is mounted slidablywithin mount openings OP defined by respective bodies 175 of the decklesystem 10. Preferably, the deckle system 10 includes an end plate 80configured to be carried adjacent to (e.g., mounted to, whether directlyor via intermediate structure) an end of the extrusion die D. In theembodiment of FIGS. 1 and 2, the end plate 80 (e.g., support regions 175thereof) defines two mount openings OP for the retractable base 50.Here, the two mount openings OP are located adjacent to (e.g., at) the“die side” of the deckle system 10. Alternatively, such mount openingscan be defined by bodies located further away from the die. Preferably,the base 50 is mounted slidably in the mount openings OP, as is perhapsbest appreciated by comparing FIGS. 7 and 8.

Thus, the deckle system 10 can advantageously include an end plate 80mounted (directly or indirectly) to an end of the die D. In preferredembodiments, a slot opening SLT passes transversely through the endplate 80 and opens to the cleaning access 57 (e.g., when the externaldeckle is in a retracted position such that the cleaning access isexposed). This is perhaps best appreciated by referring to FIG. 8. Here,an access path for the scraper SC extends through the cleaning access 57(the cleaning access is optionally configured to provide a scraperingress path that is generally or substantially parallel to the “machinedirection,” which is the general direction of extrudate flow through thedie), transversely along the slot opening SLT, and into the die'stransition zone and final land channel. In more detail, the illustratedslot opening SLT opens to, and extends between (e.g., connects), thecleaning access 57 on one side and the die's transition zone and finalland channel on another side.

In the embodiments illustrated, the deckle system 10 has a moveabledeckle carrier 120 that provides two further mount openings OP for theretractable base 50. These two mount openings OP are adjacent to (e.g.,at) the “distal side” of the deckle system 10. The term “distal” hererefers to an end, a side, etc. that is remote from the die D and/orremote from a die-side end plate 80 of the deckle system 10. Thus, theillustrated base 50 is mounted in two sets of mount openings OP definedrespectively by at least one stationary support 175/80 adjacent to thedie side of the deckle system 10 and at least one moveable support175/120, which preferably is closer to the distal end of the decklesystem than is the stationary support body. By “stationary,” it is meantthat support 175/80 is configured to remain in a stationary position atall times when the deckle system 10 is operatively mounted to the die.“Moveable” here refers to the moveable support 175/120 being configuredto move transversely relative to the fixed support 175/80. Such movementoccurs when the deckle carrier 120 is moved transversely, which can bedone to transversely position one or more internal deckles 20, 30relative to the die (so as to adjust the die's extrudate width).

The illustrated deckle carrier 120 is configured for transverse movementrelative to (e.g., selectively toward or away from) the die D and/or anend plate 80 of the deckle system. In the embodiment illustrated, thedeckle carrier is mounted for transverse movement along a plurality oftransverse support beams 140A-C. Here, the beams extend between an endplate 80 that is configured for mounting to the die and a second, distalend plate 70, which is adjacent to the distal end of the deckle system10. Both end plates 80, 70 preferably are fixed (i.e., stationary duringuse). The beams can advantageously be parallel to each other andgenerally perpendicular to the end plates and deckle carrier. Theillustrated deckle system 10 has three support beams 140A-140C, and theyare each elongated generally cylindrical beams. Here, beam 140B (the“drive shaft”) is threaded, while beams 140A, 140C are smooth. In theillustrated deckle system, a stationary frame member 110 extendsbetween, and connects, the two end plates 70, 80.

Thus, the deckle carrier 120 can advantageously comprise a body (e.g., aplate, block, platen, or an arm) through which extend a plurality oftransverse openings, optionally circular openings, in which respectivebeams are slidably and/or threadingly mounted such that the carrier ismovable transversely along the beams. While these details are notlimiting to the invention, arrangements of this nature are believed toprovide particularly quiet, stable, and easy adjustment of the decklecarrier's transverse position. Thus, these beam/carrier features canadvantageously be provided in any embodiment of the present disclosure.

The deckle carrier 120 can be moved transversely by any conventionalhydraulic or mechanical drive system 400. In the illustrated designs,the drive beam 140B is threaded and is received in an interiorlythreaded wall of the moveable carrier 120, such that rotating the driveshaft in one direction (e.g., clockwise) forces the carrier 120 to movetransversely in the inward direction, while rotating the beam in anopposite direction (e.g., counterclockwise) forces the carrier to movetransversely in the outward direction. Drive system 400 can comprise aconventional gear box, or a conventional motor can be provided.

Preferably, at least one internal deckle member 20, 30 is mounted to themovable carrier 120 such that in response to transverse movement of thecarrier, the transverse position of the (or each) internal deckle memberis adjusted. For example, the distal ends of such internal decklemembers 20, 30 can be connected (or adapted for being connected) to thecarrier 120, directly or via an intermediate mounting structure (whichmay be part of a deckle adjustment system). In the embodimentsillustrated, connected to the deckle carrier 120 are both a deckle quill20 and a secondary flag 30. Here, the quill 20 and flag 30 are removablymounted to the carrier 120, such that transverse movement of the carriercauses both of these internal deckle members 20, 30 to move transverselyrelative to the die (and/or relative to an end plate 80 of the decklesystem 10). In other cases, there may be only one internal deckleoperatively connected to the carrier. Further, it will be appreciated byskilled artisans that the particular shape and configuration of theinternal deckle member(s) will vary depending upon the particulars ofthe die being used, the product being made, etc.

Preferably, the external deckle (e.g., a retractable base 50 thereof)has a first configuration in which it is locked to the carrier 120, anda second configuration in which it is free to move transversely relativeto the carrier. FIGS. 1-4 show the first configuration (or “lockedconfiguration”) of one such external deckle, and FIGS. 8-10 show thesecond configuration (or “unlocked configuration”). In FIGS. 1-4, 7,17A, 17B, 18A-C, and 19A-C, the illustrated external deckle can belocked to the movable carrier 120 by virtue of a releasable connector(e.g., fastener) 800. Thus, when the external deckle is in its lockedconfiguration, it is secured (e.g., rigidly) to the carrier 120 so as tomove together with the carrier along the transverse axis AA (see FIG.1).

Preferably, the connector 800 can be used to unlock the external decklefrom the carrier 120. The illustrated connector 800 is a rotatable boltmounted on the external deckle and having an exteriorly threaded lengthconfigured to threadingly engage an interiorly threaded bore defined bythe carrier (or defined by a body mounted to the carrier). To unlock theexternal deckle, the illustrated connector 800 can be rotated (e.g.,counterclockwise) until its exteriorly threaded end region moves out ofthe carrier's interiorly threaded bore, thereby freeing the externaldeckle to move transversely on its own, i.e., relative to the carrier.

As is perhaps best appreciated in FIGS. 3, 4, 12, 13, 17A, and 17B, oneor both of the illustrated internal deckle members 20, 30 can beconnected to the carrier 120 in such as way as to allow each of thesedeckle members 20, 30 to have its transverse position adjustedindependently (e.g., relative to the deckle carrier, and relative toeach other). For example, a threaded rod can extend between the decklecarrier 120 and the distal end of an internal deckle 20, 30, such thatrotation of the rod moves the internal deckle 20, 30 transverselyrelative to the deckle carrier. As another alternative, a transverselyslotted arm can be attached to a distal end of an internal deckle 20,30, and a pin or another male body extending from the deckle carrier canbe slidably received in the beam's slot, with a clamp or the like usedto lock the slotted beam against the deckle carrier. Another option is adeckle adjustment like those system shown in FIGS. 12,13, 17A, 17B, and18A-C (described below). Yet another option is a deckle adjustment likethose system shown in FIGS. 19A-C (also described below). Many othervariants can be used as well. Moreover, it is not strictly required thatthe present deckle system 10 have any adjustability of this nature,although it may be preferred.

Thus, the illustrated base 50 comprises an elongated body that, when ina retracted cleaning position (e.g., when moved to a distal positionrelative to the die), bounds a cleaning access 57. As noted above, thecleaning access 57 provides a passage through which a scraper SC can beinserted to initiate cleaning of the die, e.g., a transition zonethereof. When the illustrated deckle system 10 is operatively assembledon the die D and the retractable base 50 is in its cleaning position,the cleaning access 57 is in communication with (e.g., via slit openingSLT or another opening passing through the end plate 80) the die'sorifice, final land channel, and transition zone. Thus, an operator cansimply slide the retractable base 50 away from the die D (e.g., afterunlocking the base 50 from the deckle carrier 120) until the basereaches its retracted cleaning position, and then the operator can movea scraper SC (e.g., in an upstream direction) through the cleaningaccess 57 and then transversely into the die's orifice, final landchannel, and transition zone. This is perhaps best appreciated byreferring to FIG. 8. By then moving the scraper SC along the length ofthe die (e.g., in a back and forth motion, if necessary), the die'stransition zone can be easily cleaned. Reference is made to FIGS. 9-11.In contrast to certain prior deckle assemblies, this cleaning can beperformed without first having to take apart the external deckle, thedie, or both.

Preferably, the base 50 is in its cleaning position when it is fullyretracted transversely away from the die's orifice. Thus, an operatorcan slide the base 50 away from the die (this can be done manually afterunlocking the external deckle from the deckle carrier) until there isenough clearance for the scraper SC to be inserted through the cleaningaccess 57.

The illustrated external deckle is a generally boat-shaped externaldeckle. This is perhaps best appreciated with reference to FIGS. 5-6B.Here, the external deckle comprises a base 50 having a first end region(e.g., a “die side” end region) 51. Two projection bars 58 extend fromthis end region 51 of the base 50. Preferably, the projection bars 58are at least generally parallel to each other (and to a transverselength of the die's orifice). In the illustrated design, when the base50 is in its retracted cleaning position, the two projection bars 58bound the cleaning access 57. This is perhaps best seen in FIG. 8. Here,the cleaning access 57 is bounded collectively by the base's first endregion 51 and its two projection bars 58. This particular configuration,however, is not required in all embodiments, although these projectionbar/cleaning access features can be provided in any embodiment of thepresent disclosure (as can be seen in the figures).

As noted above, the illustrated deckle system 10 has an end plate 80configured to be mounted on a side of a die D, and this end plate 80defines two transverse mount openings OP in which are slidably mountedtwo side flanges 52 of the retractable base 50. While this exemplaryarrangement has been found to provide excellent results, the presentembodiments extend to any external deckle having a cleaning access thatis spaced transversely away from the die (and/or is distal from adie-side end plate 80 of the deckle system 10).

In the embodiment of FIGS. 8-10, the cleaning access 57 is located on adistal side (i.e., the side remote from the die) of the deckle system'sdie-side end plate 80. Here, the cleaning access 57 is located at atransverse position between the die-side end plate 80 and the decklecarrier 120. More specifically, the illustrated cleaning access 57 islocated on a distal side of the die-side end plate 80, but adjacent tothat end plate. These details, however, need not be present in allembodiments.

In certain preferred embodiments, the deckle system 10 includes aninternal deckle rod 40. For example, the system 10 can include a decklerod 40 adapted (e.g., configured) to move transversely out of the die'stransition zone in response to movement of the retractable base 50 toits retracted cleaning position. As seen in FIGS. 1, 5, 6A, 6B, 7-10,17B, 18B, and 19B, some embodiments provide the retractable base 50 withan opening 43 in which the deckle rod 40 is configured to be mounted. Inthese embodiments, when the base 50 is moved transversely away from thedie D (and/or away from an end plate 80 of the deckle system 10), thedeckle rod 40 moves together with the base, such that the deckle rodmoves out of the die's transition zone. This simultaneously 1) moves thebase 50 to a configuration in which the cleaning access 57 is exposedfor use, and 2) moves the deckle rod 40 out of the die D. At this point,the deckle system is ready to be cleaned.

In other embodiments, a deckle rod is provided and is retractable fromthe die to facilitate cleaning, but the rod is held by (e.g., mountedto) another part of the deckle system. Reference is made to FIGS. 12 and13. Here, the deckle rod is mounted in an opening defined by a lowerregion, or extension, of the deckle carrier 120. Other variants of thisnature are possible as well.

As is perhaps best appreciated with reference to the embodiments ofFIGS. 7-11, a deckle quill 20 preferably is disposed at least partiallyin the die's manifold. Additionally or alternatively, a secondary deckleflag 30 can optionally be disposed in the die's preland channel. Incertain preferred embodiments, the deckle system includes a quill 20, asecondary flag 30, and a deckle rod 40, and the deckle quill 20 is afull-length quill, the secondary flag 30 is a full-length flag, and thedeckle rod 40 is a full-length rod. This, however, is not required.

Thus, certain embodiments of the invention provide a die D equipped with(e.g., in combination with) a deckle system 10 of the nature describedabove. Reference is made to FIGS. 7-11. The invention, of course, alsoextends to the deckle system 10 itself (whether or not it is provided incombination with a die). Reference is made to FIGS. 1 and 2.

In some embodiments, the invention provides a deckle system thatincludes an external deckle and a die-side end plate. When provided, thedie-side end plate 80 preferably is configured (or “adapted”) to bemounted on an end of a die D. As noted above, the external decklepreferably comprises a retractable base 50 that is moveable transverselyrelative to the end plate 80, such that the base can be movedtransversely away from this end plate to expose a cleaning access 57into which a scraper SC can be inserted. In the illustrated embodiments,a slot opening SLT passes transversely through the end plate 80 andopens to the cleaning access 57, such that an access path for thescraper SC extends through the cleaning access and transversely alongthe slot opening. When the base is in its cleaning position, thecleaning access 57 is located between the die-side end plate 80 and afirst end region 51 of the base 50. As noted above, in certainembodiments, projecting from the first end region 51 of the base 50 aretwo projection bars 58 that are at least generally parallel to eachother, such that when the base is in its retracted cleaning position,the two projection bars bound the cleaning access 57. The illustrateddie-side end plate 80 has already been described in connection with thecombination die/deckle embodiments, as have other details that need notbe repeated here.

The invention also provides methods of cleaning an extrusion die D. Thedie will commonly have a manifold, a preland channel, a final landchannel, and an orifice. A transition zone (optionally of the typedescribed above) will commonly extend from a downstream end region ofthe preland channel to an upstream end region of the final land channel.As noted above, however, the particulars of the die are not limiting tothe invention. In some of the present methods, the die D is equippedwith a deckle system 10 that includes an external deckle comprising aretractable base 50 mounted so as to be moveable transversely relativeto the die, such that the base can be moved transversely away from theorifice far enough to expose a cleaning access 57, which is spacedtransversely away from the die. In such cases, the method may comprisemoving the retractable base 50 transversely (optionally after unlockingthe base from a deckle carrier 120 of the system, e.g., such that thetransverse movement of the base is relative to the carrier) so as toexpose the cleaning access 57. In other cases, the deckle system mayhave no such retractable base, yet a cleaning access 57 locatedtransversely away from the die D is provided. The method involvesinserting a scraper SC into the cleaning access 57 (optionally by movingthe scraper in an upstream direction) and moving the scrapertransversely along the die D to clean unwanted material from the die,e.g., from a transition zone thereof. Preferably, when the scraper ismoved along the die, this involves: i) a blade portion BL of the scrapermoving transversely through the die's final land channel, and ii) a tipportion TP of the scraper moving transversely through the die'stransition zone. This is perhaps best appreciated by referring first toFIGS. 8-10 and then to FIG. 11.

As noted above, the deckle system 10 can advantageously include an endplate 80 mounted to an end of the die D. Preferably, a slot opening SLT(or another type of opening) passing transversely through the end plate80 opens to the cleaning access 57. In such cases, the method involvesinserting the scraper SC into the cleaning access 57 followed by movingthe scraper transversely through the slot opening SLT (or other opening)and into the die's transition zone and final land channel. As can beappreciated with reference to FIGS. 8-11, this involves moving thescraper from a position external to the die to a position within thedie. In some of the present embodiments, the method involves moving aretractable base 50 transversely away from the die's orifice (optionallyafter unlocking the base from a deckle carrier of the system, e.g., suchthat the base moves transversely relative to the carrier, which may bestationary during such movement of the base), so as to expose thecleaning access 57, without first disassembling the deckle system 10 orthe die D.

The invention provides a second group of embodiments wherein anextrusion die is equipped with an external deckle. Here again, theparticular die used is not limiting to the invention. Briefly, though,the die will typically have a manifold, preland channel, final landchannel, and an orifice. In the present group of embodiments, theexternal deckle has (e.g., carries) a land blade 60 that projects fromoutside of the orifice, through the orifice, and into the final landchannel.

Reference is made to FIG. 14, which is a cross-sectional view of a die Dhaving a final land channel LC into which extends a blade 60 projectingfrom an external deckle. Preferably, the land blade 60 does not extend(at least not substantially) into the preland channel PL, but rather hasa leading edge (i.e., an upstream edge) UE that terminates in the finalland channel LC (e.g., at a location where the preland channel, or atransition zone TZ, ends and the final land channel begins). Here, theillustrated land blade 60 occupies the entire length (as measured in themachine direction), or at least substantially the entire length, of thefinal land channel LC. Thus, the illustrated blade 60, when operativelypositioned for extrusion, extends from the external deckle (e.g., frombase 50) to a deckle rod 40 located in the die's transition zone TZ. Theupstream edge UE of the illustrated land blade 60 is adjacent to (andmay be in contact with) the deckle rod 40. This, however, need notalways be the case.

In the embodiment of FIG. 14, a deckle quill 20 is disposed in the die'smanifold MF, a secondary flag 30 is disposed in the die's prelandchannel PL, a deckle rod 40 is disposed in the die's transition zone,and the land blade 60 is disposed in the die's final land channel LC.This particular die and deckle arrangement is merely exemplary. As notedabove, the particulars of the die can be varied to suit differentapplications, and the number and type of deckle members will likewisevary. Thus, the present embodiments extend to any die D having a finalland channel LC into which extends a blade 60 projecting from (andoptionally being mounted on) an external deckle.

In the present embodiments, the external deckle preferably comprises aretractable base 50 mounted so as to be moveable transversely relativeto the die D. The retractable base 50 can be of the type described abovein connection with the first group of embodiments (the base can beelongated in a direction parallel to a transverse length of the die'sorifice, etc.). However, this is not required. Rather, the land blade 60of the present embodiment group can be incorporated beneficially intomany different external deckle systems.

Preferably, the land blade 60 is mounted removably on the externaldeckle, e.g., such that the blade and the external deckle are adapted tomove together along the transverse axis. As is best seen in FIGS. 5 and6A, the land blade 60 can advantageously be held (e.g., mountedremovably) between two blade holders 90A, 90B. In the embodimentillustrated, the blade holders 90A, 90B collectively form a seal bar andare mounted on the retractable base 50 (e.g., within a concave interiorregion bounded by the base). The illustrated blade holders 90A, 90B areelongated bars defining between them a slot in which the blade 60 can bemounted removably. As can be appreciated by referring to FIGS. 4, 5, 6A,6B, and 16C, a plurality of fasteners FA, BF can be extended through thebottom and/or side wall of the base 50 to secure the blade holders 90A,90B on the base, optionally in a removable manner, and/or to facilitateadjusting the position of the seal bar. If desired, the blade holderscan alternatively be fastened to the base permanently, or the blade canbe removably mounted directly to the base. As is best appreciated withreference to FIG. 16C, fasteners BF can facilitate seal bar adjustment.

The blade 60 will commonly be very thin. Typically, the blade thicknesswill substantially match the thickness of the final land channel intowhich the blade is to project. By sandwiching the blade 60 between twoholders 90A, 90B (which preferably are rigid, e.g., comprising metal),additional support and strength can be provided to the thin blade 60.Preferably, each holder defines a shoulder that bears against the bladeand has a height that is at least 25% of the blade's height (or perhapsmore preferably, at least 30%, at least 35%, or even at least 40%). Thisis perhaps best seen in FIG. 6A.

In preferred embodiments, the blade 60 is simply an elongated strip ofmetal having the desired thickness, height, and transverse length. Insuch cases, readily available shim stock can be used for the land blade.Suitable shim stock can be purchased from a variety of commercialsuppliers. Therefore, if the blade 60 needs to be replaced, the operatorwill likely have no problem replacing it; suitable shim stock willgenerally be available from a variety of local sources.

Thus, in some embodiments, the blade 60 is a strip (e.g., of metal)having an elongated transverse length and a cross section that is asimple rectangle along the entire transverse length of the strip.Reference is made to FIG. 6B.

In the embodiment illustrated, the land blade 60 (as well as bladeholders 90A, 90B) do not extend entirely along the transverse length ofthe external deckle body.

Rather, the illustrated blade 60 has a transverse length that is lessthan 80% that of the external deckle base 50. If desired, the blade'stransverse length can be less than 75%, less than 70%, or even less than65% that of the retractable base 50. This, however, is not required.

In certain embodiments, the land blade 60 is a full-length blade. Thus,when it is operatively positioned so as to extend into the die's finalland channel, a distal length of the blade 60 extends transverselyoutside of the die. This, however, need not always be the case.

As noted above, the external deckle can advantageously be part of adeckle system 10 having an end plate 80 mounted to an end of the die D.In some embodiments of this nature, the end plate 80 bounds (e.g.,defines) at least part of a slot opening SLT in which the blade 60 isreceived (e.g., slidably) when the external deckle is in use on the die(e.g., during extrusion). This is best appreciated by referring to FIGS.1 and 2.

As discussed above in connection with the first group of embodiments,the external deckle can advantageously be a generally boat-shapedexternal deckle. Additionally or alternatively, the retractable base 50can have a first end region 51 from which project two bars 58 that areat least generally parallel to each other (and to the die's orifice). Inthe illustrated embodiments, the deckle system 10 has an end plate 80that defines two transverse mount openings OP in which two side flanges52 of the base 50 are slidably mounted. As noted above, a deckle carrier120 can advantageously define two other transverse mount openings OP inwhich the two side flanges 52 are slidably mounted. It is to beappreciated, however, that these details merely reflect certainpreferred embodiments; the invention is not limited to always havingthese features

FIG. 16A depicts the leading end region of an external deckle that has aparticularly advantageous configuration. Here, ramps RMP are provided onthe external deckle such that when the external deckle is retracted, theramps release pressure between the die lip face LFSS and the seal bars90A, 90B (see FIG. 16C). This configuration makes it possible to returnthe external deckle to its operating position without having to manuallyadjust the seal bar pressure. An external deckle of this nature (e.g.,having the noted functionality, ramps, etc.) can optionally be providedin any embodiment, or any embodiment group, described herein.

In some of the present embodiments, an internal deckle rod 40(optionally having a round cross section, being formed of metal, orboth) is configured such that it moves transversely out of the die'stransition zone in response to movement of the retractable base 50 awayfrom the die (e.g., to a retracted cleaning position). As shown in FIGS.1, 5, 6A, 6B, 7-10, 17A, and 17B, certain embodiments provide theretractable base 50 with an opening 43 in which the internal deckle rod40 can be mounted. In these embodiments, when the base 50 is movedtransversely away from the die, the deckle rod 40 moves together withthe base such that the rod moves out of the die's transition zone. Thiscan simultaneously 1) move the base 50 into a configuration in which acleaning access 57 is operatively positioned/exposed, and 2) move thedeckle rod 40 out of the die.

When a deckle rod 40 is provided, the deckle system 10 preferablyincludes means for locking the rod against unintended transversemovement away from the die. As shown in FIG. 1, a lock LK for the decklerod 40 can be carried by the external deckle (e.g., on the retractablebase 50). The lock LK can be, as just one example, a rotatable key, pin,shaft, or set screw that is externally threaded and mounted in acorresponding internally threaded bore extending generally perpendicularto the long axis of the deckle rod 40. In such cases, with the lock LKin an unlocked state (so that the deckle rod 40 is free to movetransversely), the rod's transverse position can be adjusted. Then, thelock LK can be rotated such that its leading end bears forcibly againstthe deckle rod 40, thereby preventing the rod from being pushedoutwardly by fluid pressure of extrudate passing through the die.

In the present embodiments, a quill 20 preferably is disposed in thedie's manifold MF. Additionally or alternatively, a secondary flag 30can optionally be disposed in the die's preland channel PL. In certainembodiments involving a quill, flag, and deckle rod, the rod 40 is afull-length rod, the quill 20 is a full-length quill, and the flag 30 isa full-length flag. Further, the land blade 60 can be a full-lengthblade. This, however, is by no means required.

Thus, certain embodiments of the invention provide a die D equipped witha deckle system 10 of the nature described above. Reference is made toFIGS. 7-10. The invention, however, also extends to the deckle system 10itself (whether or not provided in combination with a die). Reference ismade to FIGS. 1 and 2.

In certain embodiments, the invention provides a deckle system thatincludes an external deckle comprising a transversely moveable base 50,where a blade 60 projects from the base and is configured to extendthrough an orifice, and into a final land channel, of a die D to whichthe deckle system can be mounted. Preferably, the blade 60 is configuredsuch that (when the deckle system is mounted operatively on the die) itdoes not to extend into (at least not substantially into) a prelandchannel of the die, but rather has an upstream edge that terminates inthe final land channel (and/or is located as described above). In thepresent embodiments, the blade 60 is mounted (or is adapted for beingmounted) removably on the retractable base 50. In some cases, theexternal deckle has two blade holders 90A, 90B comprising two elongatedbars defining between them a slot in which the blade 60 is mountedremovably. This is best seen in FIGS. 6A and 6B. As noted above, theblade 60 can optionally be a strip of metal having an elongatedtransverse length and a cross section that is a simple rectangle alongthe entire transverse length of the strip.

A third group of embodiments provides a deckle system having a noveldeckle adjustment mechanism. The present group of embodiments alsoextends to combination embodiments where the deckle system is providedin combination with (e.g., is mounted operatively on) a die. Methods ofusing the present deckle system (e.g., so as to adjust the transverseposition of an internal deckle member that is part of the deckleassembly) are also provided.

Reference is made to FIGS. 12, 13, 16B, 17A, 17B, 18A, 18B, and 18C.Here, the illustrated deckle adjustment mechanism includes an adjustmentbeam AB having a series of detent recesses GV spaced along a transverselength of the beam. The illustrated deckle adjustment mechanism includesa lever device (or “jack device”) 600 operably coupled with anengagement tooth TTH (as one example, see FIG. 16B). In this design, byengaging the tooth TTH with a desired one of the detent recesses GV andpivoting the lever device 600 in a first direction (to the right as seenin FIGS. 12, 13, 16B, 17A, 17B, 18A, 18B, and 18C), the adjustment beamAB can be moved in a transverse inward direction, i.e., transverselytoward a die position (to the left as seen in these figures).

In certain embodiments, an internal deckle member 20, 30 is operablycoupled to the adjustment beam AB, such that in response to transversemovement of the beam, the internal deckle member moves transversely.Thus, when an internal deckle member 20, 30 is operably coupled with(e.g., attached rigidly to an end region of) the adjustment beam AB, thetransverse position of the deckle member can be adjusted by moving thebeam transversely. As is perhaps best appreciated by referring to FIGS.13 and 16B, the distal end of the internal deckle member can beattached, directly or indirectly, to the adjustment beam. Theseattachment features can optionally be used in any embodiment of thepresent disclosure involving an adjustment beam (e.g., each adjustmentbeam AB in a given embodiment can optionally be attached to an internaldeckle member 20, 30 in the manner described in this paragraph).

In the embodiment of FIGS. 12, 13, 17A, 17B, 18A, 18B, and 18C, thedeckle system 10 includes two adjustment beams AB. However, this neednot always be the case. For example, depending on the nature of the dieand the desired extrusion process, there may be only one adjustmentbeam. Further, if three or more internal deckles were used, then therecould be three or more adjustment beams.

In the present embodiments, the adjustment beam AB has a series ofdetent recesses (grooves, blind holes, or other female detents) GVspaced along a transverse length of the beam. In the illustrateddesigns, each recess GV is a groove elongated in a directionperpendicular to a transverse axis of the deckle system (e.g.,perpendicular to the long axis of the beam AB). Preferably, between eachtwo adjacent recesses GV there is a ridge RG. In the illustratedembodiment, each ridge RG has a generally triangular cross-sectionalconfiguration, although this is not required.

The illustrated ridges RG each have a die-side face (i.e., a faceoriented generally toward the die position) and a distal-side face(i.e., a face oriented generally away from the die position). Thedistal-side faces can advantageously be inclined at steeper angles(optionally at about 90 degree angles, relative to the transverse axis)than the die-side faces. This is best seen in FIGS. 13 and 16B. Anglingthe two faces of each ridge in this manner facilitates preventingoutward transverse movement of the beam AB while simultaneously allowingtransverse inward beam movement. More will be said of this later.

Preferably, the engagement tooth TTH is configured to be engaged withany desired one of the detent recesses GV. By so engaging the tooth TTHand pivoting the lever device (or “jack device”) 600 in a firstdirection, the adjustment beam AB can be forced to move transversely. Ifdesired, the engagement tooth could be adapted to simultaneously engagemore than one detent recess.

To pivot the illustrated lever device 600, an end region LER of a leverLA (see FIG. 13) can be inserted into an opening 605 of the leverdevice, at which point the lever can be moved so as to pivot the leverdevice in the desired direction. Thus, by engaging the tooth TTH with adesired one of the detent recesses GV and pivoting the lever device 600in a first direction (to the right as seen in FIGS. 12, 13, 16B, 17A,17B, 18A, 18B, and 18C), the adjustment beam AB can be moved in atransverse inward direction (to the left as seen in these figures).After so pivoting the lever device 600 in the first direction, the leverdevice can be pivoted in an opposite, second direction so as to move thetooth TTH into engagement with a subsequent one of the detent recessesGR, at which point the lever device can be pivoted in the firstdirection again to move the adjustment beam AB further in the transverseinward direction. By repeating this series of steps (e.g., by pivotingthe lever device back and forth as described), the adjustment beam canbe moved inwardly in increments. The back-and-forth pivoting steps canbe repeated as many times as necessary until the adjustment beam AB (andan internal deckle member 20, 30 attached thereto) has moved to itsdesired position. At that point, the properly positioned internal decklemember 20, 30 can be locked in place (e.g., relative to the decklecarrier 120), as described below.

The illustrated adjustment mechanism comprises a ratchet mechanism inthat moving (e.g., pivoting) the lever device 600 in the first directioncauses the adjustment beam AB to move transversely (e.g., inwardly)whereas moving the lever device in the opposite direction does not causetransverse movement of the beam (rather, the beam can remain stationaryduring pivoting of the lever device in the second direction).

In the present embodiment group, the deckle system preferably includes alocking mechanism LKM, LKM′ (as one example, see FIG. 16B). Whenprovided, the locking mechanism can be used to prevent outwardtransverse movement of the beam AB, which may otherwise occur due tofluid pressure of extrudate passing through the die pressing outwardlyon an internal deckle coupled to the beam.

In FIGS. 16B, 17A, and 17B, the illustrated locking mechanism LKM has afree configuration, an engaged configuration, and a lockedconfiguration. This, however, is not always required. For example, thelocking mechanism could alternatively just have locked and freeconfigurations, or the locking mechanism could just have free andengaged configurations. Alternatively, the locking mechanism can havefour different settings/configurations, as described below. Manyvariations of this nature will be apparent to skilled artisans given thepresent teaching as a guide.

The illustrated locking mechanism LKM, LKM′ comprises an engagement bodyGRP (see FIG. 16B: not visible in FIGS. 18A-C) configured to bearagainst the adjustment beam AB, e.g., when the locking mechanism is ineither an engaged configuration or a locked configuration. Theillustrated engagement body GRP is spaced apart from the adjustment beamAB when the locking mechanism is in the free configuration. In thepresent design, the locking mechanism when in the free configurationallows the beam AB to move transversely in both inward and outwarddirections. In contrast, the locking mechanism when in an engaged (or“in”) configuration allows the beam to move transversely in the inwarddirection but prevents the beam from moving transversely in the outwarddirection. Thus, the present locking mechanism serves as a ratchet inthat, when in an engaged configuration, it only allows movement of theadjustment beam AB in one transverse direction (e.g., while preventingtransverse movement in the opposite direction). The illustrated lockingmechanism when in the locked configuration prevents the beam AB frommoving transversely in either the inward or outward directions.

In the illustrated embodiments, the transverse movement allowed orprevented by the locking mechanism, which has just been described, isrelative to the deckle carrier 120, which typically remains in a fixedtransverse position while the lever device 600 is used to adjust theposition of the beam AB. In alternate embodiments, there may be nomovable deckle carrier, and the noted transverse movement of the beammay be relative to a stationary end plate (or the like) to which theadjustment beam(s) may be mounted.

The locking mechanism's engagement body can take a variety of differentforms. The engagement body GRP shown in FIG. 16B has a plurality ofteeth configured to engage one or more surfaces bounding the adjustmentbeam's detent recesses GV. The illustrated teeth have distal-side facesand die-side faces, with the die-side faces being at steeper angles thanthe distal-side faces. Here, the die-side faces of these teeth areconfigured to engage the distal-side faces of the ridges RG on theadjustment beam AB. Thus, when the locking mechanism is in an engaged orlocked configuration, the resulting engagement involves confrontingpairs of surfaces bearing against one another so as to prevent outwardmovement of the adjustment beam (relative to the deckle carrier 120).The distal-side faces of these teeth are configured to engage thedie-side faces of the ridges RG on the adjustment beam AB. Due to themoderate angles of these faces, when the locking mechanism is in anengaged configuration, applying a sufficient transverse inward force tothe adjustment beam AB results in the beam moving inwardly. In theprocess, the angled die-side faces of the beam's ridges RG cam with thecorresponding distal-side faces of the engagement body's teeth, therebyallowing the engagement body GRP to ride over the ridges RG as the beamAB is forced to move inwardly. These details, however, are not limiting;the engagement body can take many other forms.

In the locking mechanism of FIGS. 16B, 17A, 17B, and 18A-C, theengagement tooth TTH is defined by a pivotable pawl PWL that is operablycoupled with a spring member SP. Here, the spring member SP isconfigured to bias the pawl PWL such that when the tooth movestransversely into alignment with one of the detent recesses GR, thespring member can forces the tooth to move into (thereby engaging) thatrecess. In FIGS. 16B, 17A, and 17B, the spring member SP is attached atone end to the lever device 600 and at the other end to the pivotablepawl PWL. In FIGS. 18A-C, the spring member SP is mounted on the leverdevice 600 in a different manner, as will now be described.

The lever (or “jack”) device 600 in FIGS. 18A-C has an end sleeve 607that can be moved axially so as to compress the spring member SP. Thiscan be done (when the lever is inserted into the lever device's opening605) by pushing the lever axially (toward the adjustment beam AB) suchthat the sleeve 607 compresses the spring member SP. This can be done tofacilitate moving the internal deckle member 20, 30 transverselyoutwardly (e.g., away from the die position). In more detail, the lockmechanism LKM′ can be put in an “out” configuration (which when selectedallows outward movement of the corresponding internal deckle member),and the lever can be advanced so as to depress the spring member SP,which causes the pawl PWL to pivot so as to move the engagement toothTTH out of engagement with the adjustment beam AB. This technique can beused to back-out the adjustment beam (and the corresponding internaldeckle member) in a controlled fashion, e.g., one groove at a time ifdesired.

The lock mechanism LKM′ in FIGS. 18A-C is different from that of FIG.16B in that it has four configurations/settings, which are referred toherein as “in,” “out,” “locked,” and “unlocked” configurations. When inthe locked configuration, the engagement body GRP bears against theadjustment beam AB so as to prevent movement of the adjustment beam (andthe corresponding internal deckle member) in either transversedirection. When in the free configuration, the engagement body GRP isspaced apart from the adjustment beam AB such that the adjustment beamand the corresponding internal deckle member are free to move in eithertransverse direction. When it is desired to move the adjustment beam andthe corresponding internal deckle member outwardly, the lock mechanismLKM′ is placed in the “out” configuration, at which point pressure fromextrudate can move the corresponding internal deckle member outwardly,during which process the lever (or “jack”) device 600 can be used tocontrol the outward movement of the deckle, as described above. When itis desired to move the adjustment beam and the corresponding internaldeckle member inwardly, the lock mechanism LKM′ is set to the “in”configuration, and the lever device 600 is used to move thecorresponding deckle member inwardly, as described above with referenceto FIGS. 16B, 17A, and 17B. In FIGS. 18A-C, the lock mechanism LKM′comprises a generally T-shaped rod TSR having a cross-pin CPN adapted tolock the T-shaped rod in any of four configurations, i.e., theabove-noted “in,” out,” “locked,” and “free” configurations.

The illustrated lever device 600 is pivotable about a first axis(defined by a first pivot point PP1). The pawl PWL is also mountedpivotally (e.g., on the lever device) and is pivotable about a secondaxis (defined by a second pivot point PP2). In the illustrated designs,these first and second axes are parallel to each other (or at leastsubstantially parallel), although this is by no means required.

In FIGS. 16B, 17A, and 17B, the illustrated locking mechanism LKMincludes a control body LS that is operable to move the lockingmechanism selectively into its desired configuration (e.g., into itsengaged, locked, or free configuration). The control body LS is shown inthe form of a rod, although many other structures can be used. Thehandle portion of the illustrated rod is shown with the lockingmechanism in the engaged configuration. In this configuration, the rodbears against a locking plate LPT, which holds the engagement body GRPagainst the adjustment beam AB. In the engaged configuration, theengagement body GRP allows the beam AB to move transversely in theinward direction, but not in the outward direction, as alreadydescribed. By moving the handle portion of the illustrated rod so thatit points upward, the locking mechanism is moved to its lockedconfiguration, which holds the engagement body GRP rigidly against theadjustment beam AB, such that the beam is not able to move transverselyin either direction. By moving the handle portion of the illustrated rodso that it points downward, the locking mechanism is moved to its freeconfiguration, which preferably involves the engagement body GRP beingspaced apart from the adjustment beam AB, such that the beam is free tomove transversely in either direction.

In the present group of embodiments, the deckle system 10 preferably hasa movable deckle carrier 120. In such cases, the deckle systempreferably includes one or more transverse beams 140A-140C along whichthe carrier 120 is moveable transversely. This is perhaps best seen inFIGS. 13 and 17A. Here, two adjustment beams AB are mounted on themoveable carrier 120. Preferably, the locking mechanism LKM, LKM′ is putin its locked configuration when it is desired to move the carrier 120transversely. By then moving the carrier 120 transversely, theadjustment beam(s) AB, the internal deckle member(s) 20, 30, and theexternal deckle 50 can be made to move transversely together with thecarrier.

As noted above, the present deckle system can be provided in combinationwith a die D (e.g., such that the deckle system is mounted operativelyon the die). In embodiments like those exemplified in FIGS. 12, 13, 17A,17B, and 18A-C, the deckle system 10 includes two adjustment beams ABand two internal deckle members 20, 30. A first 20 of the internaldeckle members is operably coupled to a first of the two adjustmentbeams AB, such that in response to transverse movement of the firstadjustment beam, the first internal deckle member 20 moves transversely.Likewise, a second 30 of the internal deckle members is operably coupledto a second of the two adjustment beams AB, such that in response totransverse movement of the second adjustment beam, the second internaldeckle member 30 moves transversely. Thus, each internal deckle member20, 30 can be transversely positioned independently of the other (andrelative to the deckle carrier). Each adjustment beam AB preferably hasa series of detent recesses GR spaced along a transverse length of thebeam, as has been described. Similarly, these embodiments preferablyinclude two locking mechanisms LKM, LKM′, two lever devices 600, twoengagement teeth TTH, etc. In such embodiments, the adjustment beams AB,locking mechanisms LKM, LKM′, lever devices 600, and engagement teethTTH preferably are mounted on a movable carrier 120 of the deckle system10, as has also been described.

The present embodiment group also provides methods for adjusting deckleposition on a die D equipped with a deckle system 10. In the presentmethods, the deckle system 10 includes a deckle adjustment mechanismcomprising an adjustment beam AB having a series of detent recesses GVspaced along a transverse length of the beam. An internal deckle member20, 30 is operably coupled to the adjustment beam AB. Preferably, thedeckle system 10 includes a lever device 600 operably coupled with anengagement tooth TTH (as described above), and the method involvesengaging the tooth in one of the detent recesses GV and pivoting thelever device so as to bias the adjustment beam AB and thereby move ittransversely (e.g., in the inward direction). This causes the internaldeckle member to move transversely (i.e., together with the adjustmentbeam), preferably relative to a deckle carrier, which will typicallyremain in a fixed transverse position during such adjustment.

As can be appreciated by referring to FIGS. 12, 13, 16B, 17A, 17B, and18A-C, the present method may involving pivoting the lever device 600 soas to provide the noted biasing and the resulting transverse movement ofthe adjustment beam AB. For example, an operator may insert the leadingend region LER of a lever LA (see FIG. 13) into the lever device 600 andthen move the lever to the right (as seen in these particular figures),thereby pivoting the lever device, and in the process forcing theadjustment beam AB to move toward the die (to the left, as seen in thesefigures).

In some of the present methods, after pivoting the lever LA once in thefirst direction, the method involves pivoting the lever in a second,opposite direction so as to move the engagement tooth TTH intoengagement with the next detent recess GV, whereafter the lever LA isagain pivoted in the first direction, so as to move the beam AB furthertoward the die position. Thus, after a first pivoting step, the methodmay subsequently comprise: i) engaging the tooth TTH in another of thedetent recesses GV, and ii) pivoting the lever device 600 so as to biasthe beam and thereby further move the beam inwardly. This process can berepeated as many times as necessary to move the beam AB (and theinternal deckle coupled to the beam) to whatever transverse position maybe desired. The present method may thus involve a ratcheting operationin which the lever device 600 is pivoted back and forth repeatedly(e.g., while the locking mechanism LKM, LKM′ is in an engaged or “in”configuration) until the internal deckle member 20, 30 reaches itsdesired position.

A fourth group of embodiments provides a novel internal deckle member 20for use with extrusion dies. Reference is made to FIG. 15. The noveldeckle member 20 (which can be referred to as a quill, plug, flag, orblade) comprises an elongated body 29 defining a transverse opening 217that opens through a side end (e.g., a distal side end) SE of the bodyand extends inwardly into the body. This opening 217 can optionally be ablind opening that extends to a wall 230 defining a blind end of theopening. In the present embodiments, an internally threaded sleeve 225is mounted in the opening 217 and defines an internally threadedpassageway 228 for receipt of a correspondingly externally threadedshaft SH. The sleeve 225 is mounted removably within the opening 217such that if internal threads 226 of the sleeve are damaged, then thesleeve can be removed and replaced with another internally threadedsleeve. This eliminates the wasteful practice of discarding the wholedeckle member simply because its internal threading has been damaged.

Typically, the deckle's elongated body 29 will be formed of one of themetals that are commonly used for internal deckle members. The internalsleeve 225 can be formed of the same metal, although this is notrequired.

In some cases, the sleeve 225 has a generally cylindrical configuration.For example, the sleeve 225 can have a cylindrical exterior shape, andit can define a cylindrical interior opening. In other cases, the sleevehas a polygonal exterior shape, and it defines a cylindrical interioropening. Other variants of this nature will be apparent to skilledartisans given the present teaching as a guide.

FIG. 15 shows one example of an internal deckle member 20 having aninternally threaded sleeve 225 in accordance with the presentembodiments. Here, an exteriorly threaded shaft SH is shown, and it willbe understood that certain embodiments provide the deckle member 20 incombination with such a shaft. For example, when operatively assembly,an externally threaded section 242 of the shaft SH is mounted in thedeckle member's internally threaded passageway 228. The illustratedsleeve 225 has a cylindrical configuration with one closed end (at theblind end of the illustrated bore 217) and one open end (at the decklebody's side SE). Alternatively, the sleeve can be open at both ends.

When a die is equipped with a deckle member 20 of the presentembodiments, the deckle member will in some cases be located (at leastin part) within the die's manifold. In other cases, a deckle memberhaving the internally threaded sleeve will be located (at least in part)in the preland channel. In some cases, the present deckle member 20 isoperatively positioned in the die's manifold, while a second internaldeckle member 30 is operatively positioned in the die's preland channel.In such cases, one or both of these internal deckle members 20, 30 canbe provided with the present internally threaded sleeve feature.Further, a deckle rod 40 can optionally be positioned downstream of thesecond deckle member 30.

It is to be appreciated that a wide variety of deckle members willbenefit from the provision of a removable internally threaded sleeve.Thus, the present sleeve feature can be incorporated into any type ofdeckle member.

In some of the present embodiments, the deckle member 20 is afull-length internal deckle. The term “full-length” is used herein torefer to a deckle member having a length in the transverse directionthat exceeds (or is at least about equal to) the maximum transverseengagement of the deckle member within the die's flow passage (whichtypically includes a manifold, preland channel, and final land channel).The present deckle member 20, however, is not required to be afull-length deckle. For example, the internally threaded sleeve featurecan be incorporated advantageously into a variety of non-full-lengthdeckle members.

FIGS. 19A-19C show another deckle system in accordance with certainembodiments of the invention. This embodiment is particularlyadvantageous in that it has a deckle adjustment mechanism that providesparticularly swift deckle adjustment. That is, when the deckleadjustment system is used to transversely move an internal deckle of thesystem, the internal deckle travels rapidly. (Referring to FIG. 19C, itwill be appreciated by skilled artisans that the deckle system has atransverse axis, which in the figure can be understood to be parallel tothe long dimension of the adjustment beams. Thus, transverse movementrefers to movement along this axis.)

The deckle system preferably comprises at least one stationary beam140A-140C and a movable deckle carrier 120 configured to movetransversely along the stationary beam(s). Preferred beam 140A-140C andcarrier 120 designs have been described in connection with otherembodiments; the same features/details can be provided in the presentembodiment, as seen in FIGS. 19A-19C. For example, there can be aplurality of such stationary beams 19A-19C, and at least one of them canadvantageously be an externally threaded beam, as described above.

Thus, in the present embodiment, the deckle adjustment mechanismpreferably is provided on (e.g., mounted on, or otherwise incorporatedonto) the moveable deckle carrier 120. The present embodiment preferablyalso includes an external deckle 50 of the nature described above (e.g.,having the cleaning access features/functionality and/or land blade 60features described above), as can also be appreciated in FIGS. 19A-19C.Thus, the features and functionalities that are general/equallyapplicable to the various deckle adjustment systems described herein, asdetailed elsewhere in the present disclosure, can be provided in thepresent embodiment (many such features are shown in FIGS. 19A-19C).These features and functionalities, however, are not described in detailhere.

The present deckle adjustment mechanism includes an elongated adjustmentbeam AB comprising a rack RK with a series of teeth TTH spaced along atransverse length of the rack. The deckle adjustment mechanism has apinion PN operably coupled with the rack RK, such that rotating thepinion in a first direction causes the adjustment beam to move in atransverse inward direction (e.g., toward the die position), whereasrotating the pinion in a second direction causes the adjustment beam tomove in a transverse outward direction (e.g., away from the dieposition). The adjustment beam AB is configured (e.g., adapted) to beoperably coupled to (in some cases, it is attached to) an internaldeckle member (e.g., when the deckle system is mounted on the die, theadjustment beam is operably coupled to an internal deckle member), suchthat the internal deckle member is configured to move transverselytogether with the adjustment beam. In the present embodiment, when thepinion is rotated, the corresponding internal deckle member travelsparticularly rapidly, thereby making adjustment extremely convenient.More will be said of this later.

The present deckle adjustment mechanism comprises a control unit CUhaving a locked configuration, a first adjustment configuration, and asecond adjustment configuration. When the control unit CU is in itslocked configuration, the corresponding internal deckle member is lockedagainst movement in either transverse direction. When the control unitis in its first adjustment configuration, the corresponding internaldeckle member is locked against outward transverse movement but is freeto move transversely inwardly in response to rotation of the pinion inthe first direction. When the control unit is in its second adjustmentconfiguration, the corresponding internal deckle is locked againstinward transverse movement but is free to move transversely outwardly inresponse to rotation of the pinion in the second direction.

As shown in FIGS. 19A-19C, the control unit CU has a control CL that canbe moved selectively into any of three positions so as to place thecontrol unit selectively into the locked configuration, the firstadjustment configuration, or the second adjustment configuration.Preferably, the control CL is an externally accessible, manually movablecontrol body. In the illustrated embodiment, the control CL is a leverswitch that can be moved into any of three positions. As is perhaps bestseen in FIG. 19A, when the lever switch is moved to its centralposition, the control unit CU is in its locked configuration, and thecorresponding internal deckle member is thus locked against movement ineither transverse direction. When the lever switch is moved to the right(as seen in FIG. 19A, e.g., to the “IN” position), the control unit CUis in its first adjustment configuration, such that the correspondinginternal deckle member is locked against outward transverse movement butis free to move transversely inwardly in response to rotation of thepinion in the first direction. When the lever switch is moved to theleft (e.g., to the “OUT” position), the control unit CU is in its secondadjustment configuration, and the corresponding internal deckle islocked against inward transverse movement but is free to movetransversely outwardly in response to rotation of the pinion in thesecond direction. Preferably, a ratchet clutch is used. Usefulcommercially available ratchet clutches are available from the LowellCorporation of West Boylston, Mass., U.S.A. (the Lowell Series 70product is one suitable example).

In FIG. 19C, the deckle adjustment mechanism is shown with exteriorhousing HOS removed, so as to illustrate the inner workings of the rackand pinion system. Here, it can be seen that the illustrated embodimentcomprises a control shaft PNS, and the pinion PN rotates with, or inresponse to rotation of, the control shaft. The illustrated controlshaft PNS is integral to the pinion PN (i.e., the control shaft andpinion are formed by a single integral shaft). This, however, is by nomeans required. For example, the control shaft and the pinion can beseparate bodies connected or otherwise operably coupled to each other.

As noted above, the present deckle adjustment mechanism system moves thecorresponding internal deckle member at a particularly fast rate oftravel. For example, the present system preferably is configured suchthat the internal deckle member moves transversely by at least 3 inches(more preferably at least 4 inches, and perhaps optimally at least 4.5inches, such as about 5 inches or more) in response to a single 360degree rotation of the control shaft PNS. In one exemplary embodiment,the pinion PN has an exterior diameter of about 1 inch with ten teethspaced about the pinion's circumference. In this particular example, theinternal deckle member moves transversely (i.e., linearly along thetransverse axis) by about 5 inches in response to a single 360 degreerotation of the control shaft PNS. These details (the rate of travel perrotation, etc.) can be varied, of course, to suit the needs of differentusers and different applications.

In FIGS. 19A-19C, the control shaft PNS is provided with an externallyaccessible, rotatable control body HX, and rotation of this body rotatesthe control shaft (which rotates the corresponding pinion), therebycausing transverse movement of the rack RK and the correspondinginternal deckle. In the embodiment illustrated, the control body HXcomprises a hex-shaped member (e.g., a hex cap). This makes it possiblefor the operator to simply use a wrench, ratchet, drill, etc. to adjustthe position of the corresponding internal deckle member. Many othercontrol body configurations are possible, however.

In the present embodiment, the illustrated adjustment beam AB iselongated in a direction parallel to (or at least substantially parallelto) the transverse axis of the deckle system, and the illustratedcontrol shaft PNS is elongated in a direction perpendicular to (or atleast substantially perpendicular to) the transverse axis. In moredetail, the illustrated control shaft PNS is mounted (on the moveabledeckle carrier 120) so as to have its long axis perpendicular to (or atleast substantially perpendicular to) both the transverse axis and themachine direction.

In the present embodiment, the deckle system is configured (e.g.,adapted) to be mounted operatively to an extrusion die D, e.g., suchthat an internal deckle (or “quill”) 20 of the deckle system is disposedat least partially within a manifold MF of the die. The deckle system ofFIGS. 19A-19C can be mounted to the die D in the same manner as is shownin FIGS. 7-11 and 14. Thus, the present embodiment also extends to acombination wherein the present deckle system is provided in combinationwith (e.g., is mounted operatively on) a die. Methods of using thepresent deckle system (e.g., so as to adjust the transverse position ofan internal deckle member that is part of the deckle assembly) are alsoprovided.

In the illustrated embodiment, the deckle system includes two internaldeckle members 20, 30 each having its own rack and pinion adjustmentmechanism. Thus, the assembly includes a second internal deckle (or“secondary flag”) 30 operably coupled with (e.g., attached to) a secondadjustment beam AB. The second adjustment beam comprises a second rackRK having a series of teeth TTH spaced along a transverse length of thesecond rack. A second pinion PN is operably coupled with the second rackRK, such that rotating the second pinion in a first direction causes thesecond adjustment beam to move in a transverse inward direction, whereasrotating the second pinion in a second direction causes the secondadjustment beam to move in a transverse outward direction. The secondadjustment beam AB is operably coupled to the second internal deckle 30such that the second internal deckle is configured to move transverselyconjointly with the second adjustment beam.

Thus, in the system shown in FIGS. 19A-19C, there are two rack & pinioncontrolled internal deckle members 20, 30. Separate control units CU areprovided so that each internal deckle member 20, 30 can be adjustedseparated. For example, if an operator wishes to fine tune thetransverse position of the quill 20 relative to the transverse positionof the secondary flag 30, then control unit CU on the left (as seen inFIGS. 19A-19C) can be operated by rotating the control body HX on thatunit CU in the appropriate direction until the quill 20 reaches itsdesired transverse position. Similarly, if the operator wishes to finetune the transverse position of the secondary flag 30 relative to thetransverse position of the quill 20, then control unit CU on the right(as seen in FIGS. 19A-19C) can be operated by rotating the control bodyHX on that unit CU in the appropriate direction until the flag 30reaches its desired transverse position. Thus, the present deckle systemcan advantageously comprises two side-by-side control units CU of thenature described.

An extrusion die system can advantageously be provided with the featuresof one, two, or more of the embodiment groups described above.

The illustrated deckle system embodiments are advantageous in that theycan be removed from an extrusion die in their entirety (i.e., as anassembly).

In some embodiments of the invention, a deckle rod 40 is disposed justdownstream from a trailing edge (i.e., a downstream edge) of a secondarydeckle flag 30. If desired, the deckle rod can be supported by a groove(e.g., a concave semi-circular groove) in the flag's trailing edge,giving it additional lateral support. While this feature is believed tobe advantageous, it is by no means required.

Further, if desired, the external deckle, the end plate, or both can beair cooled to slow nuisance leaks. This is best appreciated by referringto FIGS. 6B and 7-10. Here, it can be seen that a cool air line 710 isconfigured to deliver cool air to the external deckle (preferably so asto cool the land blade 60). As shown, the cool air line 710 extending tothe external deckle is attached to the retractable base 50. In somecases, cool air line 710 delivers cool air to one or both of the bladeholders 90A, 90B. For example, a cool air path can pass through one orboth of the illustrated blade holders 90A, 90B. In FIG. 6B, theillustrated blade holders 90A, 90B each define an air passage AC throughwhich cooling air from air line 710 can be delivered. In the embodimentillustrated, cool air from line 710 flows through a channel AC in afirst of the holders 90A, 90B, then through an opening in the blade 60,then through a channel AC in the second of the holders 90A, 90B, andfinally out of the blade holder assembly through an outlet vent definedby one or both holders 90A, 90B. This is representative of a group ofembodiments wherein an external deckle carries a land blade 60 that isair cooled, optionally by having at least one cool air channel in directcommunication with the blade and/or by having the blade itself define anopening through which a cool air path flows. The invention extends toany deckle system (and to any die equipped with such a deckle system,and to any method of using such a deckle system) having an externaldeckle provided with an air cooled land blade.

Additionally or alternatively, the deckle system can be provided with acool air line configured to deliver cool air to an end plate of thedeckle system. Reference is made to FIGS. 7-10, wherein cool air line705 is shown extending to end plate 80. Here, the cool air delivered toend plate 80 flows around the quill 20 and the secondary flag 30. Thisis representative of a group of embodiments wherein a deckle system hasa cool air line 705 configured to deliver cool air flow adjacent to(around, directly against, etc.) at least one internal deckle member.The invention extends to any such deckle system (and to any die equippedwith such a deckle system, and to any method of using such a decklesystem), whether or not it includes the features described elsewhere inthis disclosure.

Finally, the seal pressure for the external deckle can advantageously bepreset using springs, so that the operator does not have to make anyadjustments. Here again, this feature is optional.

While certain preferred embodiments have been described, it should beunderstood that various changes, adaptations and modifications may bemade therein without departing from the spirit of the invention and thescope of the appended claims.

1. An extrusion die equipped with a deckle system, the die having amanifold, a preland channel, a final land channel, and an orifice,wherein a transition zone extends from a downstream end region of thepreland channel to an upstream end region of the final land channel, thedeckle system including an external deckle comprising a retractable basemounted so as to be moveable transversely relative to the die, such thatthe base can be moved transversely away from the orifice far enough toexpose a cleaning access through which a scraper can be inserted as partof a process for moving the scraper into and transversely along the dieto clean unwanted material from the transition zone, the cleaning accessbeing spaced transversely away from the die.
 2. The extrusion die ofclaim 1 wherein the cleaning access is defined by the deckle system. 3.The extrusion die of claim 1 wherein, when the cleaning access isexposed by moving the base transversely away from the orifice, thecleaning access is bounded by a first end region of the base, the firstend region of the base being adjacent to the die.
 4. The extrusion dieof claim 1 wherein the deckle system includes an end plate mounted to anend of the die, and wherein, when the base is moved transversely awayfrom the orifice so as to expose the cleaning access, a slot openingpassing transversely through the end plate opens to the cleaning access,such that an access path for the scraper extends through the cleaningaccess, transversely along the slot opening, and into the transitionzone and final land channel.
 5. The extrusion die of claim 4 wherein thecleaning access is spaced transversely away from the deckle system's endplate.
 6. The extrusion die of claim 4 wherein the slot opening passingtransversely through the end plate opens to, and extends between, thecleaning access on one side and the transition zone and final landchannel on another side.
 7. The extrusion die of claim 1 wherein theretractable base can be moved transversely away from the orifice, so asto expose the cleaning access, without first having to disassemble thedeckle system or the die.
 8. The extrusion die of claim 1 wherein theretractable base is a concave generally boat-shaped external decklehaving an end region with two projection bars that are at leastgenerally parallel to each other and to the orifice, wherein when thebase is in a retracted cleaning position the two projection bars boundthe cleaning access.
 9. The extrusion die of claim 8 wherein the decklesystem has an end plate mounted to an end of the die, the end platedefining two mount openings in which are slidably mounted the twoprojection bars of the retractable base.
 10. The extrusion die of claim8 wherein the deckle system includes a movable carrier to which at leastone internal deckle member is mounted such that in response totransverse movement of the carrier a transverse position of saidinternal deckle member is adjusted, the retractable base being mountedto the carrier.
 11. The extrusion die of claim 1 wherein the decklesystem includes an internal deckle rod configured to move transverselyout of the die's transition zone in response to movement of theretractable base to a retracted cleaning position.
 12. The extrusion dieof claim 11 wherein the deckle system includes a deckle quill disposedin the manifold and a secondary deckle flag disposed in the prelandchannel.
 13. A deckle system that includes an external deckle and an endplate, the end plate being configured to be mounted on an end of a die,the external deckle comprising a retractable base that is moveabletransversely relative to the end plate, such that the retractable basecan be moved transversely away from the end plate so as to expose acleaning access into which a scraper can be inserted, and wherein a slotopening passing transversely through the end plate opens to the cleaningaccess, such that an access path for the scraper extends through thecleaning access and transversely along the slot opening.
 14. The decklesystem of claim 13 wherein, when the cleaning access is exposed bymoving the base transversely away from the end plate, the cleaningaccess is located between the end plate and a first end region of thebase.
 16. The deckle system of claim 14 wherein projecting from thefirst end region of the retractable base are two projection bars thatare at least generally parallel to each other, and wherein when the baseis in a retracted cleaning position the two projection bars bound thecleaning access.
 17. The deckle system of claim 16 wherein the end platedefines two mount openings in which are slidably mounted the twoprojection bars of the retractable base.
 18. The deckle system of claim13 wherein the deckle system includes a movable carrier to which atleast one internal deckle member is mounted such that in response totransverse movement of the carrier a transverse position of saidinternal deckle member is adjusted, the retractable base being mountedto the carrier.
 19. The deckle system of claim 18 wherein a quill ismounted to the movable carrier, a secondary flag is mounted to themovable carrier, and an internal deckle rod is mounted to theretractable base.
 20. A method of cleaning an extrusion die, the diehaving a manifold, a preland channel, a final land channel, and anorifice, wherein a transition zone extends from a downstream end regionof the preland channel to an upstream end region of the final landchannel, the die being equipped with a deckle system that includes anexternal deckle comprising a retractable base mounted so as to bemoveable transversely relative to the die, such that the base can bemoved transversely away from the orifice far enough to expose a cleaningaccess that is spaced transversely away from the die, the methodcomprising inserting a scraper into the cleaning access and moving thescraper transversely along the die to clean unwanted material from thedie's transition zone.
 21. The method of claim 20 wherein said movingthe scraper transversely along the die involves: i) a blade portion ofthe scraper moving transversely through the die's final land channel,and ii) a tip portion of the scraper moving transversely through thedie's transition zone.
 22. The method of claim 20 wherein the decklesystem includes an end plate mounted to an end of the die, wherein aslot opening passing transversely through the end plate opens to thecleaning access, the method comprising said inserting the scraper intothe cleaning access followed by moving the scraper transversely throughthe slot opening and into the die's transition zone and final landchannel.
 23. The method of claim 20 wherein the cleaning access isdefined by the deckle system, and wherein when the cleaning access isexposed by moving the base transversely away from the orifice, thecleaning access is bounded by a first end region of the base, the firstend region of the base being adjacent to the die.
 24. The method ofclaim 23 wherein projecting from the first end region of the retractablebase are two projection bars that are at least generally parallel toeach other, and wherein when the base is in a retracted cleaningposition the two projection bars bound the cleaning access.
 25. Themethod of claim 20 wherein the retractable base is moved transverselyaway from the orifice, so as to expose the cleaning access, withoutfirst disassembling the deckle system or the die.
 26. An extrusion dieequipped with an external deckle, the die having a manifold, a prelandchannel, a final land channel, and an orifice, the external decklehaving a blade that projects from outside of the orifice, through theorifice, and into the final land channel, such that the blade does notextend into the preland channel but rather has an upstream edge thatterminates in the final land channel.
 27. The extrusion die of claim 26wherein the external deckle comprises an elongated retractable basemounted so as to be moveable transversely relative to the die, theretractable base being elongated in a direction parallel to a transverselength of the orifice, and wherein the blade projects from theretractable base, through the orifice, and into the final land channel.28. The extrusion die of claim 27 wherein the blade is mounted removablybetween two blade holders on the elongated retractable base.
 29. Theextrusion die of claim 28 wherein the two blade holders are elongatedbars defining between them a slot in which the blade is mountedremovably.
 30. The extrusion die of claim 26 wherein the blade is astrip of metal having an elongated transverse length and a cross sectionthat is a simple rectangle along the entire transverse length of thestrip.
 31. The extrusion die of claim 26 wherein the external deckle ispart of a deckle system having an end plate mounted to an end of thedie, the blade being received in a slot opening passing through the endplate.
 32. The extrusion die of claim 31 wherein the external deckle isa concave generally boat-shaped external deckle having a first endregion from which extend two projection bars that are at least generallyparallel to each other, the end plate defining two transverse mountopenings in which are slidably mounted the two projection bars of theexternal deckle.
 33. The extrusion die of claim 31 wherein the decklesystem includes at least one internal deckle member, and a cool air lineis configured to deliver cool air through the end plate so as to flowcool air around the internal deckle member.
 34. The extrusion die ofclaim 26 wherein the blade is a full-length blade.
 35. The extrusion dieof claim 27 wherein the external deckle is part of a deckle systemcomprising an internal deckle rod configured to move transversely awayfrom the die in response to transverse movement of the retractable baseaway from the orifice.
 36. The extrusion die of claim 35 wherein thedeckle system includes a deckle quill disposed in the manifold and asecondary deckle flag disposed in the preland channel.
 37. The extrusiondie of claim 36 wherein the blade is a full-length blade, the deckle rodis a full-length rod, the deckle quill is a full-length quill, and thesecondary deckle flag is a full-length flag.
 38. The extrusion die ofclaim 26 wherein a cool air line is configured to deliver cool air tothe external deckle so as to cool the blade, the blade being directlyexposed to a cool air channel that receives flow from the cool air line.39. A deckle system that includes an external deckle comprising atransversely moveable base, wherein a blade projects from the base andis configured to extend through an orifice, and into a final landchannel, of a die to which the deckle system can be mounted, the bladebeing mounted removably on the retractable base.
 40. The deckle systemof claim 39 wherein the blade is a strip of metal having an elongatedtransverse length and a cross section that is a simple rectangle alongthe entire transverse length of the strip.
 41. The deckle system ofclaim 39 wherein the external deckle comprises two blade holderscomprising elongated bars defining between them a slot in which theblade is mounted removably.
 42. The deckle system of claim 41 wherein acool air line is configured to deliver cool air to the external deckleso as to cool the blade, the cool air line being part of a cool air paththat extends through both blade holders and through an opening definedby the blade.
 43. The deckle system of claim 39 wherein the externaldeckle includes an end plate configured to be mounted on an end of thedie, the base being moveable transversely relative to the end plate. 44.The deckle system of claim 43 wherein the movable base comprises twoprojection bars that are at least generally parallel to each other, theend plate defining two transverse mount openings in which are slidablymounted the two projection bars of the base.
 45. The deckle system ofclaim 39 wherein the blade is configured so as not to extend into apreland channel of the die but rather to have an upstream edge thatterminates in the final land channel.
 46. The deckle system of claim 39wherein the deckle system includes a movable carrier to which a quilland a secondary flag are mounted such that in response to transversemovement of the carrier, transverse positions of the quill and secondaryflag are adjusted simultaneously, the base being mounted to the carrier.47. The deckle system of claim 43 wherein the deckle system comprises aninternal deckle rod configured to move transversely relative to the endplate in response to transverse movement of the base relative to the endplate.
 48. A deckle system having a deckle adjustment mechanism, thedeckle adjustment mechanism including an adjustment beam having a seriesof detent recesses spaced along a transverse length of the beam, thedeckle adjustment mechanism including a lever device operably coupledwith an engagement tooth, wherein by engaging the tooth with a desiredone of the detent recesses and pivoting the lever device in a firstdirection the adjustment beam can be moved in a transverse inwarddirection.
 49. The deckle system of claim 48 wherein an internal decklemember is operably coupled to the adjustment beam, such that in responseto transverse movement of the beam, the internal deckle member movestransversely.
 50. The deckle system of claim 48 wherein after saidpivoting the lever device in the first direction, the lever device canbe pivoted in an opposite, second direction so as to move the tooth intoengagement with a subsequent one of the detent recesses, at which pointthe lever device can be pivoted in the first direction again to move theadjustment beam further in the transverse inward direction.
 51. Thedeckle system of claim 48 wherein the engagement tooth is defined by apivotable pawl that is operably coupled with a spring member, the springmember biasing the pawl such that when the tooth moves transversely intoalignment with one of the detent recesses the spring member forces thetooth to move into that recess.
 52. The deckle system of claim 51wherein the lever device is pivotable about a first axis, the pawl ismounted pivotally on the lever device and is pivotable about a secondaxis, the first and second axes being at least substantially parallel toeach other.
 53. The deckle system of claim 48 wherein the lever devicehas an opening into which an end region of a lever can be inserted, suchthat when the end region of the lever is received in said opening thelever can be moved so as to pivot the lever device.
 54. The decklesystem of claim 48 wherein each detent recess is a groove elongated in adirection perpendicular to a transverse axis of the deckle system. 55.The deckle system of claim 48 wherein between each two adjacent detentrecesses there is a ridge, each such ridge having a die-side face and adistal-side face, the distal-side faces being at steeper angles than thedie-side faces.
 56. The deckle system of claim 55 wherein each ridge hasa generally triangular cross-sectional configuration.
 57. The decklesystem of claim 48 wherein the deckle system includes a lockingmechanism having a free configuration, an engaged configuration, and alocked configuration, the locking mechanism comprising an engagementbody that bears against the adjustment beam when the locking mechanismis in either the engaged configuration or the locked configuration, theengagement body being spaced apart from the adjustment beam when thelocking mechanism is in the free configuration, wherein the lockingmechanism when in the free configuration allows the beam to movetransversely in both inward and outward directions, wherein the lockingmechanism when in the engaged configuration allows the beam to movetransversely in the inward direction but prevents the beam from movingtransversely in the outward direction, and the locking mechanism when inthe locked configuration prevents the beam from moving transversely ineither the inward or outward directions.
 58. The deckle system of claim57 wherein the locking mechanism's engagement body has a plurality ofteeth configured to engage one or more surfaces bounding the detentrecesses.
 59. The deckle system of claim 48 wherein the deckle systemincludes a movable deckle carrier and at least one transverse beam alongwhich the carrier is moveable transversely, the adjustment beam beingmounted on the moveable carrier.
 60. The deckle system of claim 48wherein the deckle system is provided in combination with a die, thedeckle system being mounted operatively on the die, wherein the decklesystem includes two adjustment beams and two internal deckle members, afirst of the internal deckle members being operably coupled to a firstof the two adjustment beams such that in response to transverse movementof said first adjustment beam said first internal deckle member movestransversely, a second of the internal deckle members being operablycoupled to a second of the two adjustment beams such that in response totransverse movement of said second adjustment beam said second internaldeckle member moves transversely, each adjustment beam having a seriesof detent recesses spaced along a length of the beam.
 61. A method ofadjusting deckle position on a die equipped with a deckle system, thedeckle system including a deckle adjustment device comprising anadjustment beam having a series of detent recesses spaced along atransverse length of the beam, the deckle system including an internaldeckle member operably coupled to the adjustment beam, the deckle systemhaving a detent mechanism comprising a lever device operably coupledwith an engagement tooth, the method comprising engaging the tooth withone of the detent recesses and pivoting the lever device in a firstdirection so as to bias the adjustment beam and thereby move the beamtransversely inwardly, whereby the internal deckle member is made tomove transversely inwardly together with the adjustment beam.
 62. Themethod of claim 61 wherein the deckle system includes a transverselymovable deckle carrier to which the adjustment beam is mounted, andwherein said pivoting the lever device results in transverse movement ofthe adjustment beam relative to the deckle carrier.
 63. The method ofclaim 61 wherein after said pivoting the lever device in the firstdirection, the lever device can be pivoted in an opposite, seconddirection so as to move the tooth into engagement with a subsequent oneof the detent recesses, at which point the lever device can be pivotedin the first direction again to move the adjustment beam further in thetransverse inward direction.
 64. The method of claim 61 wherein thedeckle system includes a locking mechanism having a free configuration,an engaged configuration, and a locked configuration, wherein thelocking mechanism when in the free configuration allows the beam to movetransversely in both inward and outward directions, wherein the lockingmechanism when in the engaged configuration allows the beam to movetransversely in the inward direction but prevents the beam from movingtransversely in the outward direction, and the locking mechanism when inthe locked configuration prevents the beam from moving transversely ineither the inward or outward directions, the method comprising placingthe locking mechanism into its engaged configuration prior to saidpivoting the lever device in the first direction.
 65. An internal decklemember for an extrusion die, the deckle member comprising an elongateddeckle body defining a transverse opening that opens through a side endof the deckle body and extends inwardly into the deckle body, wherein aninternally threaded sleeve is mounted within the blind opening anddefines an internally threaded passageway for receipt of acorrespondingly externally threaded shaft, the sleeve being mountedremovably within the opening such that if internal threads of the sleeveare damaged, then the sleeve can be removed and replaced with areplacement internally threaded sleeve.
 66. The internal deckle memberof claim 65 wherein the sleeve has a generally cylindricalconfiguration.
 67. A deckle and shaft assembly including the internaldeckle member of claim 65, wherein the deckle member is provided incombination with said externally threaded shaft, an externally threadedsection of the shaft being mounted in said internally threadedpassageway.
 68. A die assembly including the deckle and shaft assemblyof claim 67, wherein the deckle member and said externally threadedshaft are provided in combination with the extrusion die, the die havinga manifold, at least part of the deckle member being located within themanifold.
 69. The die assembly of claim 68 wherein the deckle member isa full-length internal deckle.
 70. A deckle system comprising astationary beam and a movable deckle carrier configured to movetransversely along the stationary beam, wherein a deckle adjustmentmechanism is provided on the moveable deckle carrier, the deckleadjustment mechanism including an adjustment beam comprising a rack witha series of teeth spaced along a transverse length of the rack, thedeckle adjustment mechanism including a pinion operably coupled withsaid rack, wherein rotating the pinion in a first direction causes theadjustment beam to move in a transverse inward direction whereasrotating the pinion in a second direction causes the adjustment beam tomove in a transverse outward direction, the adjustment beam beingoperably coupled to an internal deckle such that the internal deckle isconfigured to move transversely conjointly with the adjustment beam, thedeckle adjustment mechanism comprising a control unit having a lockedconfiguration, a first adjustment configuration, and a second adjustmentconfiguration, wherein when the control unit is in its lockedconfiguration the internal deckle is locked against movement in eithertransverse direction, wherein when the control unit is in its firstadjustment configuration the internal deckle is locked against outwardtransverse movement but is free to move transversely inwardly inresponse to rotation of the pinion in said first direction, and whereinwhen the control unit is in its second adjustment configuration theinternal deckle is locked against inward transverse movement but is freeto move transversely outwardly in response to rotation of the pinion insaid second direction.
 71. The deckle system of claim 70 wherein thecontrol unit includes an externally accessible, manually movable controlthat can be moved selectively into any of three positions so as to placethe control unit selectively into the locked configuration, the firstadjustment configuration, or the second adjustment configuration. 72.The deckle system of claim 70 wherein the deckle adjustment mechanismincludes a rotatable control shaft, and the pinion rotates with thecontrol shaft, the deckle adjustment mechanism being configured suchthat the internal deckle moves transversely by at least four inches inresponse to a single 360 degree rotation of the control shaft.
 73. Thedeckle system of claim 72 wherein the control shaft is provided with anexternally accessible, rotatable control body, and wherein rotation ofsaid control body rotates the control shaft, whereby the pinion rotates,thereby transversely moving the rack and the internal deckle.
 74. Thedeckle system of claim 72 wherein the adjustment beam is elongated in adirection substantially parallel to a transverse axis of the decklesystem, and the control shaft is elongated in a direction substantiallyperpendicular to said transverse axis.
 75. The deckle system of claim 70wherein the deckle system is mounted operatively to an extrusion die,the internal deckle being mounted at least partially within a manifoldof the die.
 76. The deckle system of claim 70 wherein the deckle systemfurther includes a second internal deckle, wherein there is provided asecond adjustment beam comprising a second rack with a series of teethspaced along a transverse length of the second rack, and a second pinionis operably coupled with the second rack, such that rotating the secondpinion in a first direction causes the second adjustment beam to move ina transverse inward direction whereas rotating the second pinion in asecond direction causes the second adjustment beam to move in atransverse outward direction, the second adjustment beam being operablycoupled to the second internal deckle such that the second internaldeckle is configured to move transversely conjointly with the secondadjustment beam.